Concerns: pushword/flat
POST_DEPLOY_LOCAL was the last line of a set -e push: a remote chain dying after composer update skipped it — exactly the moment the rebuilt container leaves opcache stale and every PHP host answering 500 until the reset runs. It now fires from an exit trap armed once the push starts mutating production, so a failed deploy still resets (and the push still exits with the failure code). A push aborted at a confirmation prompt touched nothing and still skips it.